1、MIL-S-lLI37LIC b 77777Ob Ollbbb 2 MIL-S-14374C 11 February 1283 SUPERSEDING MIL-S-l4374B(MU) 2 October 1969 b1LITARY S PE C IF ICAT I ON SILICA GEL, IRON FREE This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification c
2、overs one iron-free type of silica gel (hereinafter referred to as silica gel). 2. APPLICABLE WCUMENTS 2.1 Government documents. 2.1.1 Specifications, standards, and handbooks. Unless otherwise specified, the following specifications, standards, and handbooks of the issue listed in that issue of the
3、 Department of Defense Index of Specifications and Standards (DoDISS) specified in the solicitation form a part of this specification to the extent specified herein. SPECIFICATIONS FEDERAL PPP-C-186 - Containers, Packaging and Packicg for Drugs, Chemicals, and Pharmaceuticals : Beneficial comments (
4、recommendations, additions, deletions) and any perti- : : nent data which may be of use in improving this document should be addressed: : to: Commander, US Army Armament Research and Development Command, ATTN: : DRDAR-TSC-S, Aberdeen Proving Ground-, MD 21010 by using the self-addressed : : Standakd
5、ization Document Improvement Proposal (DD Form 1426) appearing at : : the end of this document or by letter. FSC 6810 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STANDARDS MILITARY MIL-STD-195 - Sampling Procedures and Tables for Inspection by MI
6、L-STD-1188 - Commercial Packaging of Supplies and Equipment Attributes I (Copies of specifications, standards, handbooks, drawings, and publications required by manufacturers in connection with specific acquisition functions should be obtained from the contracting activity or as directed by the cont
7、ract- ing officer . ) 2.2 Other publications. The following documents form a part of this speci- fication to the extent specified herein. The issues of the documents which are indicated as DoD adopted shall be the issue listed in the current DoDISS and the supplement thereto, if applicable. ASTM STA
8、NDARDS C169 - Chemical Analysis of Soda-Lime and Borosilicate Glass Dl193 - Reagent Water D1895 - Apparent Density, Bulk Factor, and Pourability of Plastic Ell - Wire-Cloth Sieves for Testing Purposes Ma te rials (Application for copies should be addressed to ASTM, 1916 Race Street, Philadelphia, PA
9、 19103.) (Industry association specifications and standards are generally available for reference from libraries. and using Federal agencies. ) They are also distributed among technical groups 2.3 Order of precedence. In the event of a conflict between the text of this specification and the referenc
10、es cited herein, the text of this specifica- tion shall take precedence. 3, REQUIREMENTS 3.1 Chemical and physical characteristics. Silica gel shall conform to the chemical and physical characteristics of table I when tested as specified there- in. 3.2 Particle size. Silica gel shall have a particle
11、 size distribution con- fordng to table II when tested as.specified in 4.2.4.8. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-L4374C b m 77777Ob OLLbbb2 b m MIL-S-14374C TABLE I. Chemical and physical characteristics . Characterlsti : Requi
12、rement : Test paragraph : * . : Silicon dioxide, percent by weight, minimum : 99.7 : Apparent density, pounds per cubic foot : 37 to 43 : Iron, parts per million, maximum 20 : Chloride, parts per million, maximum 2 : Contamination : To pass test : pH 6 to 7 , : Noisture, percent by weight, maximum 3
13、, O . TABLl$ II. Particle size distribution 4.2.4.1 4.2.4.2 : 4.2.4.3 4.2.4.4 4.2.4.6 402.4.5 402.4.7 * : Passing sieve : Retained on sieve : Percent by weight : : (micrometers) : (micrometers) 3 Minimum : Miximum : . . . . . - . - T.r- 600 * O 9 600 425 =. 2 * 425 250 80 : - : 20 180 - 3 150 3 - 25
14、0 18 O : 150 -_- - 4. QUALITY ASSURqNCE PROVISIONS 4.1 Responsibility fQr inspection. Unless otherwise specified in the con- trgct or purchase order, the coritrgctor is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract o
15、r purchase order, the contractor may use his own or any other facilities suitable far the performance of the inspection requirements speci- fied herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspections set forth in the specification where such
16、 inspections are deemed necessary to assure supplies and services conform to prescribed requirements. 4.2 Quality conformance inspection. 4.2.1 Lotting. j A lot shall consist of the silica gel produced by one manu- ifacturer, at one plant, from the same materials, and under essentially the same manu
17、facturing conditions provided the operation is continuous. In the event the process is a batch opgration, each batch shall constitute 9 lot (see 6.3). 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 2 2 SampLng. 4.2.2.1 For examination of packagi
18、ng. Sampling shall be conducted in accord- ance with MIL-STD-105. 4.2.2.2 For test. Sampling for test shall be conducted in accordance with A representative specimen of approximately 125 grams (8) shall be table III. removed from each sample container and placed in a suitable clean, dry container la
19、beled to identify the lot and container from which it was taken. TABLE III. Sampling for test : Number of containers in batch or lot : Number of sample containers : I 3 to 150 : 3 . 151 to 1,200 . 5 . 1,201 to 7,000 8 . 7,001 to 20,000 10 Over 20,000 . 20 b 1 I . . . . . * : . 4.2.3 Inspection proce
20、dure. 4.2.3.1 For examination of packaging. The sample unit shall be one filled unit or shipping container, as applicable, ready for shipment. Sample unit and shipping containers shall be examined for the following defects using an AQL of 4.0 percent defective: (a) (b) Container not as specified (c)
21、 Container closure not as specified , (d) Container damaged or leaking (e) Unitization not as specified (f) Marking incorrect, missing, or illegible Contents per container not as specified 4.2.3.2 For test. Each sample specimen taken in 4.2.2.2 shall be tested as specified in 4.2.4. rejection of the
22、 lot represented. Failure of any test by any specimen shall be cause for 4.2.4 Tests. Water in accordance with ASTM D1193 type III and reagent grade chemicals shall be used throughout the tests. Where applicable, blank determinations shall be run and corrections applied where significant. Tests shal
23、l be conducted as follows: 4.2.4.1 Silicon dioxide. Determine the percent silicon dioxide in accord- ance with ASTM C169, using the procedure which determines percent silicon dioxide 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4.2.4.2 Apparent
24、density. Determine the apparent density in accordance with ASTM D1895 and convert to pounds per cubic foot. 4.2.4.3 Iron. Weigh 2.000 g of the specimen into a 100-milliliter (ml) platinum evaporating dish. Add 2 ml of concentrated sulfuric acid and 10 ml of concentrated hydrofluoric acid, and evapor
25、ate sowly on a hot plate under a hood to fumes of sulfur trioxide. Continue theevaporation until the volume is approximately 0.7 ml. Remove from the hot plate, cool, slowly add an additional 10 ml of concentrated hydrofluoric acid, and repeat the evaporation to fumes of sulfur trioxide. Cool, add 10
26、 ml of 4-percent boric acid solution, and evaporate to approximately 1 ml. Cool, quantitatively transfer the concen- trate to a 50-ml volumetric flask, and make up to volume with water. Transfer a 2-ml aliquot of the solution to a color comparison tube and dilute to 50-1 with water. Add 30 to 50 mil
27、ligrams (mg) of ammonium persulfate crystals and 3 ml of ammonium thiocyanate solution. The color developed shall be no darker than that produced in a control containing 0.01 mg of iron ions in an equal volume of solution containing the quantities of reagents used in the specimen test. 4.2.4.4 Chlor
28、ide. Weigh 10 g of the specimen and dissolve in 50 ml of water. Bring the solution to a boil and continue boiling for 2 to 3 minutes. Decant 25 ml and to it add 1 ml of concentrated nitric acid and 1 ml of 0.1N silver nitrate solution. Any turbidity produced shall be no greater than that produced in
29、 a control containing 0,Ol mg of chloride ion in an equal volume of solution containing the quantities of reagents used in the specimen test. 4.2.4.5 Moisture. Weigh to the nearest milligram approximately 2 g of the specimen into a tared weighing dish. Dry to a constant weight in an oven at 105“ + 5
30、OC, cool to room temperature in a desiccator, and weigh to the nearest milligram. Calculate the percent by weight moisture as follows: I 100 (A - B) W Percent by weight moisture =i where: A = Weight of dish and specimen before drying, in grams, B = Weight of dish and specimen after drying, in grams,
31、 and W = Weight of specimen in grams. 4.2.4.6 Contamination. Add 1 g of specimen to 50 ml of 10-percent sodium hydroxide solution. minutes. The specimen shall show no appreciable darkening after 5 4.2.4.7 pH. Weigh 5.0 g of specimen into a glass-stoppered Erlenmeyer flask and dissolvin 50 ml of carb
32、on dioxide- and ammonia-free water. flask, shake occasionally, and let stand overnight. Determine the pH of the aqueous extract by means of the glass electrode method within 10 minutes after it is exposed to the air. Stopper the 5 Provided by IHSNot for ResaleNo reproduction or networking permitted
33、without license from IHS-,-,-MIL-S-14374C 4.2.4.8 Particle size. Use tared sieves conforming to ASTM Ell. Amange receiving pan, 150 micrometer, the sieves in the following ascending order: 180 micrometer, 250 inicrometer, 425 micrometer, 600 micrometer, and cover. Place 100 3- 1 g of the specimen in
34、 the top sieve (600 micrometer), cover, and shake for 10 ininutes by means of a mechanical shaker geared to produce 300 - 4- 15 gyrations and 150 3- 10 taps of the striker per minute. retained on each sieve and the naterial on the receiving pan and calculate the percent by weight retained by each si
35、eve and the percent by weight passing the 150 inicrometer sieve as follows : Weigh the material 100 (A - B) W Percent by weight retained on applicable sieve = 100 (C - D) W Percent by weight: passing 150 micrometer sieve wh re: A = Weight of applicable sieve and specimen retained, in grams, B SI Wei
36、ght of applicable sieve, in grams, C = Weight of receiving pan and specimen cdllected, in grams, D = Weight of receiving pan, in grams, and W = Weight of specimen in grams. 5. PACKAGING 5.1 Unit packing, level B. A quantity of one pound (44.2 or -0 ounces) of The closure shall silica gel shall be pa
37、cked in a bottle conforming to group A, class 1, type optional, style 2, grade optional, closure A of PPP-C-186. be provided with an aluminum foil liner. provided with an outer seal conforming to seal A of PPP-C-186. with closures in place and seals applied shall pass the leakage test specified in P
38、PP-C-186, The filled and closed bottle shall be The bottles 5.2 Packing, industrial. Silica gel, unit packed as specified in 5.1, shall be packed in accordance with MIL-STD-1188. 5.3 Unitization. palletized in a manner to assure carrier acceptance, safe delivery to first des- tination, and stable st
39、ackability in storagel Uniform quantities of packs of silica gel shall be 5.4 Marking. Unit packs and packs of silica gel shall be marked in accordance with MIL-STD-1188. Pallet loads shall be marked to agsure carrier acceptance and safe, timely delivery to the destination. Containers shall be marke
40、d to show date of manufacture and the lot number of the silica gel. 6. NOTES 6.1 Intended use. Silica gel is intended for use in the preparation of impregnated gels and in the manufacture of sampling tubes. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from I
41、HS-,-,-6.2 crkyfi$g dmd AcquikLLidn doeurhents shouLd specify the title, number, and date OE this bpenifikatbon. 6.3 - Batch. A bateh is de#ihed as that quantity of material which has been manufactured by come unit chemical Ptocess or subjected to some physical mixing operation intended to make the
42、final product substantially uniform. 664 Stgnific,nt.places. For the purpose of determining conformance with this Specification, ari dbserved or calculated value should be rounded off “to the nearest unit” in the Last right-hand place of figures used in expressing the limiting value, in accordance w
43、ith the rounding-off method of ASTM E29. Custodiati: Preparing activity: Amy EA Army - EA Review activities: Project No. 6810-B376 AI$IIY MI) bw - GGS 60s; &X%?NIkfENT PRINTING OFFICE 1983-605-034/2465 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
